<!DOCTYPE html>
<html lang="zh-CN">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width,initial-scale=1">
    <title>js实用方法 | 掏钱的机器猫</title>
    <meta name="generator" content="VuePress 1.9.7">
    <link rel="icon" href="/vue-admin-ui/assets/logo.png">
    <meta name="description" content="掏钱的机器猫的个人博客,记录随笔与学习笔记，个人项目等">
    <meta name="viewport" content="width=device-width,initial-scale=1,user-scalable=no">
    
    <link rel="preload" href="/vue-admin-ui/assets/css/0.styles.fb55c927.css" as="style"><link rel="preload" href="/vue-admin-ui/assets/js/app.21d1badc.js" as="script"><link rel="preload" href="/vue-admin-ui/assets/js/3.d02ddc64.js" as="script"><link rel="preload" href="/vue-admin-ui/assets/js/1.38c8ef5a.js" as="script"><link rel="preload" href="/vue-admin-ui/assets/js/29.65b69672.js" as="script"><link rel="preload" href="/vue-admin-ui/assets/js/8.79ebffb7.js" as="script"><link rel="prefetch" href="/vue-admin-ui/assets/js/10.d9a14dc0.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/11.284df538.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/12.530bdb86.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/13.3dde5c1a.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/14.e18000c4.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/15.65b98979.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/16.953b2589.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/17.d6be13fa.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/18.a10ec5a3.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/19.f2ef083a.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/20.9e024a1a.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/21.b818c6cd.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/22.f3716a62.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/23.42bfb2a3.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/24.0382e6dc.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/25.9b1cf793.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/26.626abbca.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/27.d6b1a7e8.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/28.7381bce0.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/30.70062600.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/31.036bec0e.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/32.1ec26c99.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/33.69485516.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/34.30a7370c.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/35.1e72f74a.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/36.a6aaafe3.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/4.984f5e20.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/5.2cbf0f84.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/6.eab8daa0.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/7.41bb2a3c.js"><link rel="prefetch" href="/vue-admin-ui/assets/js/9.e9ae19e3.js">
    <link rel="stylesheet" href="/vue-admin-ui/assets/css/0.styles.fb55c927.css">
  </head>
  <body>
    <div id="app" data-server-rendered="true"><div class="theme-container" data-v-2d5f533b><div data-v-2d5f533b><div id="loader-wrapper" class="loading-wrapper" data-v-d48f4d20 data-v-2d5f533b data-v-2d5f533b><div class="loader-main" data-v-d48f4d20><div data-v-d48f4d20></div><div data-v-d48f4d20></div><div data-v-d48f4d20></div><div data-v-d48f4d20></div></div> <!----> <!----></div> <div class="password-shadow password-wrapper-out" style="display:none;" data-v-64685f0e data-v-2d5f533b data-v-2d5f533b><h3 class="title" style="display:none;" data-v-64685f0e data-v-64685f0e>掏钱的机器猫</h3> <!----> <label id="box" class="inputBox" style="display:none;" data-v-64685f0e data-v-64685f0e><input type="password" value="" data-v-64685f0e> <span data-v-64685f0e>Konck! Knock!</span> <button data-v-64685f0e>OK</button></label> <div class="footer" style="display:none;" data-v-64685f0e data-v-64685f0e><span data-v-64685f0e><i class="iconfont reco-theme" data-v-64685f0e></i> <a target="blank" href="https://vuepress-theme-reco.recoluan.com" data-v-64685f0e>vuePress-theme-reco</a></span> <span data-v-64685f0e><i class="iconfont reco-copyright" data-v-64685f0e></i> <a data-v-64685f0e><span data-v-64685f0e>Ethan</span>
              
            <span data-v-64685f0e>2018 - </span>
            2022
          </a></span></div></div> <div class="hide" data-v-2d5f533b><header class="navbar" data-v-2d5f533b><div class="sidebar-button"><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" role="img" viewBox="0 0 448 512" class="icon"><path fill="currentColor" d="M436 124H12c-6.627 0-12-5.373-12-12V80c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12zm0 160H12c-6.627 0-12-5.373-12-12v-32c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12zm0 160H12c-6.627 0-12-5.373-12-12v-32c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12z"></path></svg></div> <a href="/vue-admin-ui/" class="home-link router-link-active"><img src="/vue-admin-ui/assets/logo.png" alt="掏钱的机器猫" class="logo"> <span class="site-name">掏钱的机器猫</span></a> <div class="links"><div class="color-picker"><a class="color-button"><i class="iconfont reco-color"></i></a> <div class="color-picker-menu" style="display:none;"><div class="mode-options"><h4 class="title">Choose mode</h4> <ul class="color-mode-options"><li class="dark">dark</li><li class="auto active">auto</li><li class="light">light</li></ul></div></div></div> <div class="search-box"><i class="iconfont reco-search"></i> <input aria-label="Search" autocomplete="off" spellcheck="false" value=""> <!----></div> <nav class="nav-links can-hide"><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title"><i class="iconfont reco-document"></i>
        插件文档
      </span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/vue-admin-ui/category/vue-admin-ui-lib/" class="nav-link"><i class="iconfont undefined"></i>
    vue-admin-ui-lib
  </a></li><li class="dropdown-item"><!----> <a href="/vue-admin-ui/category/submit-valid/" class="nav-link"><i class="iconfont undefined"></i>
    submit-valid
  </a></li><li class="dropdown-item"><!----> <a href="/vue-admin-ui/category/open-utils/" class="nav-link"><i class="iconfont undefined"></i>
    open-utils
  </a></li></ul></div></div><div class="nav-item"><a href="/vue-admin-ui/handle/handle/method.html" aria-current="page" class="nav-link router-link-exact-active router-link-active"><i class="iconfont undefined"></i>
    手写代码
  </a></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title"><i class="iconfont reco-message"></i>
        个人站点
      </span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="https://gitee.com/ethan6" target="_blank" rel="noopener noreferrer" class="nav-link external"><i class="iconfont reco-mayun"></i>
    Gitee
    <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></li><li class="dropdown-item"><!----> <a href="https://github.com/Ethan66" target="_blank" rel="noopener noreferrer" class="nav-link external"><i class="iconfont reco-github"></i>
    Github
    <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></li></ul></div></div> <a href="https://github.com/Ethan66/vue-admin-ui" target="_blank" rel="noopener noreferrer" class="repo-link"><i class="iconfont reco-github"></i>
      Github
      <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></nav></div></header> <div class="sidebar-mask" data-v-2d5f533b></div> <aside class="sidebar" data-v-2d5f533b><div class="personal-info-wrapper" data-v-ca798c94 data-v-2d5f533b><img src="/vue-admin-ui/assets/logo.png" alt="author-avatar" class="personal-img" data-v-ca798c94> <h3 class="name" data-v-ca798c94>
    Ethan
  </h3> <div class="num" data-v-ca798c94><div data-v-ca798c94><h3 data-v-ca798c94>24</h3> <h6 data-v-ca798c94>文章</h6></div> <div data-v-ca798c94><h3 data-v-ca798c94>11</h3> <h6 data-v-ca798c94>标签</h6></div></div> <hr data-v-ca798c94></div> <nav class="nav-links"><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title"><i class="iconfont reco-document"></i>
        插件文档
      </span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/vue-admin-ui/category/vue-admin-ui-lib/" class="nav-link"><i class="iconfont undefined"></i>
    vue-admin-ui-lib
  </a></li><li class="dropdown-item"><!----> <a href="/vue-admin-ui/category/submit-valid/" class="nav-link"><i class="iconfont undefined"></i>
    submit-valid
  </a></li><li class="dropdown-item"><!----> <a href="/vue-admin-ui/category/open-utils/" class="nav-link"><i class="iconfont undefined"></i>
    open-utils
  </a></li></ul></div></div><div class="nav-item"><a href="/vue-admin-ui/handle/handle/method.html" aria-current="page" class="nav-link router-link-exact-active router-link-active"><i class="iconfont undefined"></i>
    手写代码
  </a></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title"><i class="iconfont reco-message"></i>
        个人站点
      </span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="https://gitee.com/ethan6" target="_blank" rel="noopener noreferrer" class="nav-link external"><i class="iconfont reco-mayun"></i>
    Gitee
    <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></li><li class="dropdown-item"><!----> <a href="https://github.com/Ethan66" target="_blank" rel="noopener noreferrer" class="nav-link external"><i class="iconfont reco-github"></i>
    Github
    <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></li></ul></div></div> <a href="https://github.com/Ethan66/vue-admin-ui" target="_blank" rel="noopener noreferrer" class="repo-link"><i class="iconfont reco-github"></i>
      Github
      <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></nav> <ul class="sidebar-links"><li><section class="sidebar-group depth-0"><p class="sidebar-heading open"><span></span> <!----></p> <ul class="sidebar-links sidebar-group-items"><li><a href="/vue-admin-ui/handle/handle/designMode.html" class="sidebar-link">js设计模式</a></li><li><a href="/vue-admin-ui/handle/handle/method.html" aria-current="page" class="active sidebar-link">js实用方法</a></li><li><a href="/vue-admin-ui/handle/handle/native.html" class="sidebar-link">js原生代码实现</a></li></ul></section></li></ul> </aside> <div class="password-shadow password-wrapper-in" style="display:none;" data-v-64685f0e data-v-2d5f533b><h3 class="title" style="display:none;" data-v-64685f0e data-v-64685f0e>js实用方法</h3> <!----> <label id="box" class="inputBox" style="display:none;" data-v-64685f0e data-v-64685f0e><input type="password" value="" data-v-64685f0e> <span data-v-64685f0e>Konck! Knock!</span> <button data-v-64685f0e>OK</button></label> <div class="footer" style="display:none;" data-v-64685f0e data-v-64685f0e><span data-v-64685f0e><i class="iconfont reco-theme" data-v-64685f0e></i> <a target="blank" href="https://vuepress-theme-reco.recoluan.com" data-v-64685f0e>vuePress-theme-reco</a></span> <span data-v-64685f0e><i class="iconfont reco-copyright" data-v-64685f0e></i> <a data-v-64685f0e><span data-v-64685f0e>Ethan</span>
              
            <span data-v-64685f0e>2018 - </span>
            2022
          </a></span></div></div> <div data-v-2d5f533b><main class="page"><div class="page-title" style="display:none;"><h1 class="title">js实用方法</h1> <div data-v-3b7f5bdf><i class="iconfont reco-account" data-v-3b7f5bdf><span data-v-3b7f5bdf>Ethan</span></i> <i class="iconfont reco-date" data-v-3b7f5bdf><span data-v-3b7f5bdf>2020-10-23</span></i> <!----> <i class="iconfont reco-tag tags" data-v-3b7f5bdf><span class="tag-item" data-v-3b7f5bdf>实用</span></i></div></div> <div class="theme-reco-content content__default" style="display:none;"><h1 id="js实用方法"><a href="#js实用方法" class="header-anchor">#</a> js实用方法</h1> <h2 id="数组方法"><a href="#数组方法" class="header-anchor">#</a> 数组方法</h2> <div class="code-wrap"><!----> <div class="code--demo"><div class="code-content"><div>
    克隆数组，合并数组，拼接数组，代替apply, 字符串转数组，类数组转数组
  </div> <div class="code-tips"></div></div></div> <div class="code--segment"><highlight-code lang="js">
    const arr = [...arr1]
    const arr = [...arr1, ...arr2]
    arr.push(...arr1)
    Math.max(...[x, y]); // Math.max.apply(null, [x, y])
    [...&quot;hello&quot;];
    [...Arguments, ...NodeList]
  </highlight-code></div> <div class="code--button">显示代码</div></div> <div class="code-wrap"><!----> <div class="code--demo"><div class="code-content"><div>数组去重</div> <div class="code-tips"></div></div></div> <div class="code--segment"><highlight-code lang="js">
    // [...new Set(arr)]
    // Array.from(new Set(arr))
    Array.prototype.distinct = function() {
      const map = {}
      const result = []
      for (const n of this) {
          if (!(n in map)) {
              map[n] = 1
              result.push(n)
          }
      }
      return result
    }
    [1,2,3,3,4,4].distinct(); //[1,2,3,4]
  </highlight-code></div> <div class="code--button">显示代码</div></div> <div class="code-wrap"><!----> <div class="code--demo"><div class="code-content"><div>
    数组排序
  </div> <div class="code-tips"></div></div></div> <div class="code--segment"><highlight-code lang="js">
    Array.prototype.bubleSort=function () {
      let arr=this,
          len = arr.length;
      for (let outer = len; outer &gt;= 2; outer--) {
        for (let inner = 0; inner &lt;= outer - 1; inner++) {
          if (arr[inner] &gt; arr[inner + 1]) {
            //升序
            [arr[inner], arr[inner + 1]] = [arr[inner + 1], arr[inner]];
            console.log([arr[inner], arr[inner + 1]]);
          }
        }
      }
      return arr;
    }
    [1,2,3,4].bubleSort() //[1,2,3,4]
    // 选择排序
    Array.prototype.selectSort=function () {
      let arr=this,
          len = arr.length;
      for (let i = 0, len = arr.length; i &lt; len; i++) {
    for (let j = i, len = arr.length; j &lt; len; j++) {
    if (arr[i] &gt; arr[j]) {
      [arr[i], arr[j]] = [arr[j], arr[i]];
    }
    }
    }
    return arr;
    }
    [1,2,3,4].selectSort() //[1,2,3,4] 
  </highlight-code></div> <div class="code--button">显示代码</div></div> <h2 id="对象方法"><a href="#对象方法" class="header-anchor">#</a> 对象方法</h2> <h3 id="对象浅拷贝"><a href="#对象浅拷贝" class="header-anchor">#</a> 对象浅拷贝</h3> <div class="code-wrap"><!----> <div class="code--demo"><div class="code-content"><div class="code"><code>var obj1 = { x: 1, arr: [1, 2] }; var obj2 = {}</code> <code>obj1.arr[0] = 3; obj1.x = 5</code> <code>obj2 =&gt; { x: 1, arr: [3, 2] }</code></div> <div class="code-tips"></div></div></div> <div class="code--segment"><highlight-code lang="js">
    var obj2 = { ...{ x: 1 } }
    var obj1 = Object.assign({}, { x: 1 })
  </highlight-code></div> <div class="code--button">显示代码</div></div> <h3 id="对象深拷贝"><a href="#对象深拷贝" class="header-anchor">#</a> 对象深拷贝</h3> <div class="code-wrap"><!----> <div class="code--demo"><div class="code-content"><div class="code"><code>var obj = {a: {b: {c: 1}}, b: 3, d: [{e: 5}]}</code> <code>var result = clone(obj)</code> <code>obj.a.b.c = 2</code> <code>obj.d[0].e = 6</code> <code>console.log(result)</code></div> <div class="code-tips"></div></div></div> <div class="code--segment"><highlight-code lang="js">
    function clone (obj) {
      let type = Object.prototype.toString.call(obj)
      if (type !== '[object Object]' &amp;&amp; type !== '[object Array]') return obj
      let res = Array.isArray(obj) ? [] : {}
      for(let key in obj) {
        if (obj.hasOwnProperty(key)) {
          res[key] = clone(obj[key])
        }
      }
      return res
    }
  </highlight-code></div> <div class="code--button">显示代码</div></div> <h3 id="实现双向数据绑定"><a href="#实现双向数据绑定" class="header-anchor">#</a> 实现双向数据绑定</h3> <div class="code-wrap"><!----> <div class="code--demo"><div class="code-content"><div>页面中有input输入框，和span标签，input输入内容span内容改变，js修改input的value，span的内容改变</div> <div class="code-tips"></div></div></div> <div class="code--segment"><highlight-code lang="js">
    var obj = {}
    var input = document.querySelector('input')
    var span = document.querySelector('span')
    function define(obj, key) {
      Object.defineProperty(obj, key, {
        get () {
          return tmp
        },
        set (val) {
          tmp = val
          span.innerHTML = val
        }
      })
    }
    define(obj, 'value')
    input.addEventListener('input', function (e) {
      obj.value = e.target.value
    })
  </highlight-code></div> <div class="code--button">显示代码</div></div> <h3 id="对象监听"><a href="#对象监听" class="header-anchor">#</a> 对象监听</h3> <div class="code-wrap"><!----> <div class="code--demo"><div class="code-content"><div>监听对象里的所有属性，属性改变了console一下</div> <div class="code-tips"></div></div></div> <div class="code--segment"><highlight-code lang="js">
   let info = {};
    function observe(obj) {
      if (!obj || typeof obj !== &quot;object&quot;) {
        return;
      }
      for (var i in obj) {
        definePro(obj, i, obj[i]);
      }
    }
<div class="language- extra-class"><pre><code>function definePro(obj, key, value) {
  observe(value);
  Object.defineProperty(obj, key, {
    get: function() {
      return value;
    },
    set: function(newval) {
      console.log(&quot;检测变化&quot;, newval);
      value = newval;
    }
  });
}
definePro(info, &quot;friends&quot;, { name: &quot;张三&quot; });
info.friends.name = &quot;李四&quot;;
</code></pre></div></highlight-code></div> <div class="code--button">显示代码</div></div> <h2 id="proxy深监听对象"><a href="#proxy深监听对象" class="header-anchor">#</a> proxy深监听对象</h2> <h2 id="rem基本设置"><a href="#rem基本设置" class="header-anchor">#</a> rem基本设置</h2> <div class="code-wrap"><!----> <div class="code--demo"><div class="code-content"><div>页面宽度改变，html的font-size改变</div> <div class="code-tips"></div></div></div> <div class="code--segment"><highlight-code lang="js">
    (function (doc, win) {
      var el = doc.documentElement,
        type = 'orientationchange' in window ? 'orientationchange' : 'resize',
        fn = function () {
          var clientWidth = el.getBoundingClientRect().width
          var fs = 100 * (clientWidth / 750)
          el.style.fontSize = fs + 'px'
        }
      win.addEventListener(type, fn, false)
    })(document, window)
  </highlight-code></div> <div class="code--button">显示代码</div></div> <h2 id="节流"><a href="#节流" class="header-anchor">#</a> 节流</h2> <div class="code-wrap"><!----> <div class="code--demo"><div class="code-content"><div>点击第一次触发，在规定时间内点击不生效</div> <div class="code-tips"></div></div></div> <div class="code--segment"><highlight-code lang="js">
    function throttle (fn, delay) {
      var before = new Date().getTime()
      var now = ''
      return function (...arg) {
        if (!now) {
          now = before = new Date().getTime()
          return fn.apply(this, arg)
        }
        now = new Date().getTime()
        if (now - before &gt; delay) {
          before = now
          return fn.apply(this, arg)
        }
      }
    }
  </highlight-code></div> <div class="code--button">显示代码</div></div> <h2 id="防抖"><a href="#防抖" class="header-anchor">#</a> 防抖</h2> <div class="code-wrap"><!----> <div class="code--demo"><div class="code-content"><div>点击最后一次生效</div> <div class="code-tips"></div></div></div> <div class="code--segment"><highlight-code lang="js">
    function debounce (fn, delay) {
      let timer = ''
      return function (...arg) {
        timer &amp;&amp; clearTimeout(timer)
        timer = setTimeout(() =&gt; {
          clearTimeout(timer) // 此时timer不为空
          timer = ''
          return fn.apply(this, arg)
        }, delay)
      }
    }
  </highlight-code></div> <div class="code--button">显示代码</div></div> <h2 id="实现懒加载"><a href="#实现懒加载" class="header-anchor">#</a> 实现懒加载</h2> <div class="code-wrap"><!----> <div class="code--demo"><div class="code-content"><div class="code"><code>var html = `<ul><li><img src="" data="./imgs/1.png" alt=""></li> <li><img src="" data="./imgs/2.png" alt=""></li> <li><img src="" data="./imgs/3.png" alt=""></li> <li><img src="" data="./imgs/4.png" alt=""></li> <li><img src="" data="./imgs/5.png" alt=""></li> <li><img src="" data="./imgs/6.png" alt=""></li> <li><img src="" data="./imgs/7.png" alt=""></li> <li><img src="" data="./imgs/8.png" alt=""></li> <li><img src="" data="./imgs/9.png" alt=""></li> <li><img src="" data="./imgs/10.png" alt=""></li></ul>`</code></div> <div class="code-tips"></div></div></div> <div class="code--segment"><highlight-code lang="js">
    document.body.innerHTML = html
    var imgList = document.querySelectorAll('img')
    // 可视窗口高度
    var clientHeight = window.innerHeight || document.documentElement.offsetHeight || documnent.body.offsetHeight
    window.addEventListener('scroll', function () {
      var scrollTop = document.documentElement.scrollTop || document.body.scrollTop;
      [...imgList].forEach(img =&gt; {
        var diff = clientHeight + scrollTop - img.offsetTop
        if (diff &gt; 0 &amp;&amp; diff &lt; img.offsetHeight + clientHeight) {
          img.src = img.getAttribute('data')
        }
      })
    })
  </highlight-code></div> <div class="code--button">显示代码</div></div> <h2 id="常用的正则"><a href="#常用的正则" class="header-anchor">#</a> 常用的正则</h2> <div class="language- line-numbers-mode"><pre class="language-text"><code>//匹配 16 进制颜色值
var color = /#([0-9a-fA-F]{6}|[0-9a-fA-F]{3})/g;

//匹配日期，如 yyyy-mm-dd 格式
var date = /^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[12][0-9]|3[01])$/;

// 手机号码正则
var phone = /^1[34578]\d{9}$/g;

//用户名正则
var username = /^[a-zA-Z\$][a-zA-Z0-9_\$]{4,16}$/;

//Email正则
var email = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;

//URL正则
var urlP= /^((https?|ftp|file):\/\/)?([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w \.-]*)*\/?$/;
</code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br></div></div></div> <footer class="page-edit" style="display:none;"><!----> <div class="last-updated"><span class="prefix">上次更新: </span> <span class="time">2022/7/8 上午10:51:20</span></div></footer> <!----> <!----> <!----></main> <!----></div></div></div></div><div class="global-ui"><div class="back-to-ceiling" style="right:1rem;bottom:6rem;width:2.5rem;height:2.5rem;border-radius:.25rem;line-height:2.5rem;display:none;" data-v-c6073ba8 data-v-c6073ba8><svg t="1574745035067" viewBox="0 0 1024 1024" version="1.1" xmlns="http://www.w3.org/2000/svg" p-id="5404" class="icon" data-v-c6073ba8><path d="M526.60727968 10.90185116a27.675 27.675 0 0 0-29.21455937 0c-131.36607665 82.28402758-218.69155461 228.01873535-218.69155402 394.07834331a462.20625001 462.20625001 0 0 0 5.36959153 69.94390903c1.00431239 6.55289093-0.34802892 13.13561351-3.76865779 18.80351572-32.63518765 54.11355614-51.75690182 118.55860487-51.7569018 187.94566865a371.06718723 371.06718723 0 0 0 11.50484808 91.98906777c6.53300375 25.50556257 41.68394495 28.14064038 52.69160883 4.22606766 17.37162448-37.73630017 42.14135425-72.50938081 72.80769204-103.21549295 2.18761121 3.04276886 4.15646224 6.24463696 6.40373557 9.22774369a1871.4375 1871.4375 0 0 0 140.04691725 5.34970492 1866.36093723 1866.36093723 0 0 0 140.04691723-5.34970492c2.24727335-2.98310674 4.21612437-6.18497483 6.3937923-9.2178004 30.66633723 30.70611158 55.4360664 65.4791928 72.80769147 103.21549355 11.00766384 23.91457269 46.15860503 21.27949489 52.69160879-4.22606768a371.15156223 371.15156223 0 0 0 11.514792-91.99901164c0-69.36717486-19.13165746-133.82216804-51.75690182-187.92578088-3.42062944-5.66790279-4.76302748-12.26056868-3.76865837-18.80351632a462.20625001 462.20625001 0 0 0 5.36959269-69.943909c-0.00994388-166.08943902-87.32547796-311.81420293-218.6915546-394.09823051zM605.93803103 357.87693858a93.93749974 93.93749974 0 1 1-187.89594924 6.1e-7 93.93749974 93.93749974 0 0 1 187.89594924-6.1e-7z" p-id="5405" data-v-c6073ba8></path><path d="M429.50777625 765.63860547C429.50777625 803.39355007 466.44236686 1000.39046097 512.00932183 1000.39046097c45.56695499 0 82.4922232-197.00623328 82.5015456-234.7518555 0-37.75494459-36.9345906-68.35043303-82.4922232-68.34111062-45.57627738-0.00932239-82.52019037 30.59548842-82.51086798 68.34111062z" p-id="5406" data-v-c6073ba8></path></svg></div></div></div>
    <script src="/vue-admin-ui/assets/js/app.21d1badc.js" defer></script><script src="/vue-admin-ui/assets/js/3.d02ddc64.js" defer></script><script src="/vue-admin-ui/assets/js/1.38c8ef5a.js" defer></script><script src="/vue-admin-ui/assets/js/29.65b69672.js" defer></script><script src="/vue-admin-ui/assets/js/8.79ebffb7.js" defer></script>
  </body>
</html>
